Semi-automatic telephone system.



E A. MELLINGER. SEMI-AUTOMATIC TELEPHONE SYSTEM.

APPLICATKON HLED MAY), 1313 Patented J 11110 13, 1916.

fwcd M54 UNXTED STATES PAT. NZ? QFFICE.

EDNARD A.

MELLINGER, OF CHiCAGO, KLLINQIS. ASSIC QGR- TC! AUTOMATIC ELECTRIC CQll'DPANY, OF CHICAGQ, ILLZNO'L'EZ, (1031 03531031 032 ELLINOIS.

SEMI-AUTGMATXC TELEPHONE SYSTEJ.

Application filed Flay 5, 1913. Serial Ifil'e.

or. l 'zlcanci-crn: lie it. own til at l, EDWARD A GER. a n oi the United My inventitm is otiapteol for use in a tem in which calls are received on a manual hoarch "from which hoam the call is to he extended through autonmtic switches to the called line. in such a svsteim accord my invention, each of the ope ators upon the manual bUHlklilllS a calling device for transi'nitting iingri to control these automutic switchee, and each operator has acto a plurality of trunk lines leading to these automatic switches.

An object of my intention is to provide moans HSSt 1ml with the culling devices whereby when an operator opt-1 her talk 11p. 1 it ing devioe in uccoi'tlanmi with the number, this nailing (lQ KO is autoni: connected with an idle trunk line.

A further object the provision signal associated with each trunk line to x r 1 1. 3. M13 it indudte nitn nlncn trons ti. to nip: om he has been connected.

A further object is the provision of in for :uitomaticullv disconnecting the null device from the selected trunk when the operator plugs into the jack of the t-rnnlx: in ortler to extend the talking connection over this trunk.

These anti other objects of my invention will he more clearly understood by reference to the accompanying drawings, in which I have represented diagrammatically a manual calling line and an operators cord cir cuit connected with trunk line. it is to he understood that this trunk line repiw onts one of a plurality of trunks which extend to an automatic exchmige. a connection to it called suhscrihefs line lining: completed Specification ofliettsrs Eatent.

Potent-oil June 13, 1916 and connecswitches henot thought 'n the tllfiW- totioni may he of anv "fi -cored type and, as shown the eivcr i transmit t K i jer and coni once the line of the sub- 7 ovitletl with on answe'ing r or 11 e nniltiplo jacks J, a double mound line relay 13, cut-ol t-relav ll and line hung u V adapted for use :wo manual lines or wool line with the aufhis cord comprises the ling plugs P and through the condoms .lno ;-;o;:m- .'isory circuits of the cowl ore controllm'l through the medium (ii t .2 rm 3L 32 and 33. The relays l llllil are doublewound polarized relays ot uction. As shown h vciin the who .m relay is mounted iwtviiill the hvo mn'os of ii Unhape-il per-- lllfllli'ltt in not, tvvo vvii lings of the relays Ill and 33 are normally bridged in series across the cord circuit through the cnotmts (it the relays 31 and then either o the reinvs 31 or 32 is energized, one Winding ot the corresponding reloy 3G or conneotcu to ground and the other winding of said relay is connected-to the non-grounded tern'iinzil of the battery. The cord cirouit is provided with the usual ringing l: l and KR An answering key K is provided for the purpose of connecting the operators talking set S with the cord. The trunk circuit leading to the automatic exchange is provided With a multiple jack J .rpon each operators position in the manual board. The sleeve conductors of the jack 5 are connected to the battery lead 35 thr mgzh the Winding of a relay 34. Each hu' a tor connect", tonnitic cf ni trunk also provided with a visual busy signal n each opemtors position. Each trunk also provided with a slow acting control am. 0 (he ada fiwiilch E may contra t iperatm's mm have of trunk 'iines may be arm f (:21 used '1 in: r, mes

he banks 0f iire 0W f," wing given a g'vnc nl (1e 22;):1'111115, at Wlii no 1 now the radii! b-r: wiz inezl in 4w 7 mums? S'fl iw NW2 03 mins a-"mnection \VlLh 21 trunk line loading! in 3 1 :11: 1. rnnmtic exchanga The remm'nfi f thwwmver :15 the calling substation (13050. :4 :xcmszs the line, thruugh the tram-aunt" thslvhy energizing; {he Zine. rehxy 1itantra office in" the usurs. n'lzlnnmx 115 S, upnn (-mar 010149; the.

grm noting hmp, the (mm W line iump 121112,; 5.} I112? uutimaatzv. 4V

operator 1113mm" t0 epemte ihs; m

:1 th numb m dir-awnneciing said calling device QUE Hunk: win-n the operator connects 1 wnmifi with flu fad-r an the svleuted trunks when the, opemtuy ummrcts the curd dun. a word Summit a iii mid mi ling; to minim-2 I trunk said Hm nmkvr counoulun signal MAN! :1

(ml with paid mining arm 'i "ire-um wanting in )iwg in bu, :itml with Ja'mf i W nn d1. 'unncab hm w wmiwl [131:3 Mnitrolled by said last mentioned leasing said other switch.

Signed by me at, London, 22nd day of April, 1913.

EDW'ARD A. ME Witnesses:

\VAL'rER H. DERRIMIAN, AIBERT J ve:

means for re- England, this LLINGER. 

